Multicanonical Monte Carlo study of the BER of an all-optically 2R regenerated signal

Using a numerical procedure based on the multi-canonical Monte Carlo (MMC) algorithm, we compute the bit error rate (BER) at the output of a Mamyshev-type all-optical regenerator. For the specific device considered, this BER is degraded as compared to its value at the input to the regenerator, even though the Q-factor is improved. In absolute terms, the output BER decreases when the bandwidth of the optical filter placed before the regenerator to limit the amount of entering noise is decreased. We also present evidence that the degradation of the BER caused by the regenerator is due to high sensitivity of the output signal to small variations of the input signal shape. To our knowledge, this fact has not been pointed out in earlier studies of regenerators. In addition to the previous results, the modification of the MMC procedure that we proposed and used in this paper can be, in a certain sense, parallelized. When it is practical to do so, our procedure provides significant saving of the computational time over the standard MMC simulation.